Ulcerative colitis is a disease of increasing prevalence for which at present the only satisfactory treatment is the administration of salazopyrin, which has the following structural formula: ##STR2##
However, one serious disadvantage of salazopyrin is that it is broken down in the intestinal tract to give sulphaphyridine which gives rise to undesirable side effects. Furthermore, salazopyrin is insoluble in water.
We have now found that when the pyridylsulphamoyl moiety of salazopyrin is replaced by certain non-heterocyclic organic radicals, compounds are obtained which are very useful for the treatment of ulcerative colitis and have the great advantage that breakdown thereof in the intestinal tract does not give rise to undesirable metabolic products. Furthermore, many of them are soluble in water, which is advantageous for ease of administration, and have a very low acute toxicity.